Door



Feb. 9 1926.

r J. DART DOOR Filed April 12, 1924 2 Sheets-Sheet 1 Feb. 9 1926.

J. DART DOOR 2 sheets-sheet 2 Filed April l2 1924 'nung' @J 4MM/UZ VS' Patented F 9, i926.

UNITED STATES PAT ENT rOF'F'IC El I JAMES DART, OF CHICAGO, ILLINOIS.

noon.

Application filed Apri112, 192% vSerial 110.706,015.

.To all 'whom t may concern.:

Be it known that I, .Innes DART, a citiA zen of the "United States, residing at Chicago, in the countyof Cook and State of Illinois. have `invented a certain new 4and useful Improvement in Doors, of which the following is a full, clear,conc`ise, and exact description, reference vbeing` had to the accompanying drawings, forming apart of Y slow to open, and, in many instances, may

have an initial friction sufficient tov prevent opening'` at all. I believe this to be one of the primary difiiculties involved, and one of the chief causes for the failure of devices previously proposed. A

The primary object .of the invention is to overcome the foregoing difficulty.

Further objects and advantages of the invention will become apparent as the description proceeds. In the accompanying drawings Fig. l is a side elevation and Fig. 52 an end elevation partly in section, of one embodiment of the invention; V

Fig. 3 is a detail indicating an alternative arrangement for the carrying track;

Figs. 4 and 5 are side and endielevations similar to Figs. land 2 of another type of construction Figs. Gand 7 are detail sections 6 6 and 7-7 of Fig. 4;

Fig. 8 is a section similarto Fig. 7 of a modified construction; y F ig. 9 is a sidev elevation of the parts shown in Fig. 8; and

Fig. 10 is a detail ofan automatic stopping bumper.

on lines In the embodiment of the invention se` looted for illustration in Figs. l and 2, the door sill l0 is suitably mounted for limited vertical movement. Door l2 is sli'dably mounted on alhorizontal track 14 by suitlow the track;

able means such as wheels 16and .18 riding on top of thetrack and "wheel20 riding be- A y K lVheel 20is nearer pulley 16 than 18. This facilitates the kconstrue` tion of Fig. `3, in which the end section of track 22 is pivoted at 24and provided with up when WheellS `rides off it, and increase the vertical clearance at-.the center of the door opening.

-a small counterweight 26 so that `it will tip The doors 12 illustrated are double doors,

but as the construction on` both sides of the door. opening may be identical, only one side has been illustrated. Y

Rollers 28lie under sill 10 on the ends of rocking levers 30 pivoted at 32. connect with .one end of rocking levers 36 ,pivoted at 38. The other'ends of levers`36 connect with tension risers 40. ,v

Posts 42support fixed pivots 44, onwhich are magnifying lever`s`46, having theirshort.V

ends pivoted to risers40` and theirv long nends `connected to links `48. Each link 48 actuv'ates a bell cranklever 50, connected through .link52 with a back lever 54 actuating link Links 34 Y 56 and link -58'pi`voted at 60 to the door 'if structure vto pull the same'back. Bell crank 62v connected to the ypivotbetween links 56 and 58 carries a counterweight 64 to return the door to closed position. `A suitable dashpot structure 62 may be connected to the system at any convenient or preferred point. i

Grangplanks 64 connect lthe sill 10 with the surrounding foundation structure 66. It will be apparent that the downward force on sill 10 Will increase uniformly as a Weight passes yacross gangplanksr 64 from Zero When the Weight first comes onthe `gangplanks `to fullvalue when the Weight `reaches lthe'near edge of the sill. "In the case of a four- `Wheeled. vehicle, the widthofthe sill plus the length vof the gangplank must be equal to the wheelbase of theychicleto maintain a constant load' on sill 10 ,during passage ofthe vehicle through thedoor. If this is the case, the front Wheels will-reach the far edge of thesill, at the same instant that the rear Wheels start across `one gangplank. In practice, this need only be approximated, and the front Wheel might'trav- 1.

erse as much as one-,third of the far gang plank before therear Wheels need start up the other gangplank. :This is particularly true, because the Wheel baseusually increases with. the weight of lthe vehicleuThus, .a

device designed Yto maintainv full load throughout, with a standardvehicle of relatively light weight and short wheel base.-

would hav'e the parts so proportioned that Vthe door would be held Vopen at all times during passage of a heavier vehicle of longer .wheel base, although while eithei' set of wheels were directly on the sill 10, thek load thereon would be in excess of that necessary tovhold thedoor open.

' It will also be obvious that the total dimensions of the device measured between the remoteends of the gangplanks may be decreased by increasing the width v of' the sill. Thus, by adding'one'foot to the width of the sill, one foot can be subtracted from Y the length of each gangplank, and the ltotal ever all dimensions decreased byy one foot.

It is obvious that this change in relative dimensions may be continued until sill 10 becomes practically a wide lscale platform,

with short gangplanks to bridge' the discontinuity between its edges and the surrounding foundation structure.

TnFig. 1, the parts are shown Iin thc nnloaded position with the door* closed. lllt will vbe notedfthat lever 30' and linkV 231i are almost inali-gnmenu'and that lever 36 and riser tOgare also only vslightly out of alignment. This will jresult inaffverylarge magnification of the 'force applied to roller 28'.4 Of course, this limplies also a different ratio of movement between parts 10 'and 12. As the roller 28 moves down, .lever 30 and link will move'into'a position'more nearly at right angles to each other, and a similar vmovement out of relative alignment will'occur between lever 86 and riser 40." ThiSwill increase the relative movement of door 12 withrespect to sill 10, with a corresponding decrease in the effective force tending to' open the door. Assume, for a practical example, that the vertical movement of *the sill is a total oflfour inches, and the horizontal movement of tliedoor must totalffour feet, at the beginning of the movement, the movement ratio between the parts will be f much less than twelve to one, and atpthe end V.the door to perhaps thirty vto one.

ofvk the'movement much greater than twelve' to one. Thus the toggle action of the linkage mightbe designed to makethe. initial .after and92.

An extension link '.102 is pivoted to the door.

wheels 1G, 2O and 18, andinaterially diminish friction in the same.

shaft 68 carrying forked arms 70 engaging pinsprojecting from vertical plungers T2, to assist in controlling the movement of the sill and holding it horizontal at all times.

The toggles for producing the variations in effective leverage have been shifted, only one togglebeing positioned before the magnifying lever, and the other being positioned the same. Furthermore, the first toggle, is positioned close to the point et magnification ofmovement so that the heavy forces generated thereby need only be carried through a short distance. Thus riser 74 acting in tension to support the ends of sill 10 directly extends up parallel with post 76. vMagnifying lever 7 8 is keyed on pintle 80. and extends down beside thev door, Vith the parts'of the relative diii'iensions indicated, considerably less than ninety dcgress of rotation of arm 78 will open `the door. Adjacent pintle 80 and for ashort distance below thesame'post 7G is reinforced by a duplicate channel section 184, united therewith by plates 8G to form a box vcolnmni` A fixed pintle 88 near the bottom of the short box column carries rocker 90 pivotedV at 92 to theupper end of vriser 7l `and at 94 to the lower end of short link 96 which actilates pintle 8O through crank arm 98; AV turnbnckle 100 may be piovided for adjusting the length of link `VIt will'bev observed that pivots 88 and 9i are almost in line with link 9G when the stantially at right angles v'to link 96, but

pivot 92. will be fast approaching alignment of the crank 'arm represented by pivots 88 and 92 with tension link 74. It will be apparent that a variation in the effective lcverage overl a very wide range, and, .to a certain extent, the shape of the curve representing such leverage at different positions ofthe door, may be controlled by the rela'- tive positioning of thek three pivots 88, 91

lower en -d of arm 78, and to a bracket 104: vcarried by door 12. It will be apparentthat links78 and 102 form a second toggle when the door is closed, to yincrease the effective leverage during the' initial opening movenient. As the force acting on bracket 104i can only be parallel tol link 102, it will be observed that this large initial force not only pulls the door toward an open position, but will lift it upward, and tend to carry a substantial fraction of the weight of the This will relieve the load on guide vArmy 78 is rolonred in the other, direction at 105l and terminates in a counterfil) curve ot net et'fective foreetending to open the door tor the dilierent positions of the saine.

Any suitable nieaiis tor 'checking' the movement ot' the door may be employed.- I have illustrated stationary dashpot 110 to cushion the opening movement. 'The closing'movement, may effectively be taken care ot' by a rubber bumper` strip 112 along the edgev ot the door. As the inward movement of the tivo doors represents displacement of equal masses in opposite directions, they ivill not have any recoil with respect to the track or ,building when they meet..V

However, to prevent excessive forces being developed by the sudden stopping ot' counterweight 108 through toggle links 102 and 78, I prefer to position an adjustable bumper 114i to engage said links at the end oi the closingmovement near theirV point of pivotal connection.

Referring non' to Figs. 8, 9 and 10, I have illustrated a pivoted door 16 provided with a short crank arm 118 on its pin-'tie 120. The eye 122 of rod 124iengages the end of crank arm 118. Post 120 supports a pintle 128 for a. rocking lever 130 extended rearwardly to support eounterweight 132 and at its forivard end pivoted to arni 124i at 134. Tension member 136 is connected to an intermediate point -on arm 130. It Will be apparent that a downward pull on tension member 136 Will rotate lever 130 ina closely Wise direction, and that at the beginning ot such movement levers 130 and 124: are nearly in line and form a toggle to magnify the torce applied to the door. Tension member 13G may be an extension of riser 74, or the upper end of link 96. y

Then the door opens by rotation, I .may provide a bumper 138 supported on door 116 by parallelograin vlinks 140. Spring `1.4[2

barely supports the Weight ot bumper 138 and link 14:0. In case someperson should be standing near the door when it began to open and could not get out ot the way, bumper 138 would be depressed to sivingthe toe ott-lie loiver parallelograin link into any one of a series ot notches 14/1 to stop the opening movement ot the door.

lVithout further elaboration, the toregoing will so fully explain the gist ot my invention that others may, by applying curw rent knowledge, readily adapt the same for use under various conditions ot service( It` will, tor instance, be obvious that the variable effective leverage between sill and door may be ,provided by means ot cains instead oit levers. These and manyother alte ations and inodilieations may readily be made by those skilled in the art Without eliminating certain features which may properly be said to constitute the essential iteins or' novelty involved, which items are intended to be detined and secured to nie-by `the followingl claims: i

I1. In a device-ot the'class described, in combination, a Vv-.fall having an opening, a` vertically n'iovable Asill under said opening,

gangplanks extending in opposite directions from said sill, lined supports tor the remoteends ot said gangplanks, the proximate ends ot said gangplanks resting on said sill,v

a slidab'le door for said opening, tension means supporting` said sill, a fixed pivot, a. rotatable@memberon said pivot rotated by said `tension member, a second Fixed pivot above the door, a erankarm on` said pivot, a link pivoted to said rotatable member and crank arm, means for adjusting the effective length ot said link, a long arm projecting doivn from said second pivotbeside the door, and an extension pivotally con# vnected dto the door and said longarm, said extension and saidv adjustable link being both almost in alignmentwvith the parts actuating them when the door is closed.

"2. In a device of the class described, in combination, a Wall having an opening, a vertically movable sill under said opening,

vgangplanks extending in opposite directions from said sill, tixed supports for the remote ends of said gangplanks, the proxiniate ends of said gangplanks resting on said sill, a slidable door tor said opening, tension means supporting said sill, a liXed pivot, a rotatable member on said pivot rotated by said tension member, a second fixed pivot above the doei', a crank arm on said pivot,

a linkpivoted to said rotatable member and crank arm, a long arm projecting' down troni said second pivot beside the door, and an extension pivotally connected to the door and said long` arm, said extension and said adjustable link being both almost in alignment with the parts actuating them when the door is closed.

In a device ot the class described, in combination, a Wall having an opening, a vertically movable sill under said opening, gangplanks extending in opposite directions from said sill, tired supports ttor the remote ends of said gangplanks, the proximateV ends of said gangplanks resting on said sill, a slidable door tor said opening, tension means supporting said sill, a `tived pivot, a rotatable member on said pivot rotated by said tension member, a second lined pivot above the door, a crank arm on said pivot, a link pivoted to said rotatable member and crank arm, and connections between said sec-ond fixed )ivot andthe door for opening the same, said link being almost in alignment with the part actuating it When the door is closed. y Y

4l. In a device of the class described, in combination.y a Wall having,` an opening, a vertically movable sill under said opening, gangplanks extending in oppoeite directions 'from said fill, ixed supports ior the remote ends of said gangplanks, the proximate ends of Said' zqangplanks resting' onrsaid sill, a lelidable door for said openinpnteneion means supporting SaidA Sill, a fixed pivot,Y a rotatable' member on Said pivot rotated by said tension member, a second lined pivot above the door,l a crank arm on said pivot, a link `pivoted to said rotatable member and crank arm, a long arm projectingv down from said second pivot beside the door, and an eXtene sion pivotally connected to the'door and Said long arm, said extension being almost in alignment with the arm actuating it when i my name this 10th day of April, 1924.

the door is closed.

In a device of the class` described, 1n

combination, a Wall having` an opening', a movable horizontal sill under Sald opening,

Vnlungers secured to the bottom side of said sill for guidingvthe sill in a vertical direction, pins `projecting from said plungers and forked arms engaging with said projecting pins to assist in constraining the movement oi" the sill and holding it hori- `zontal at all times.

6. In av` device of the class describechin combination, 1a Wall having an opening, a movable Sill under said opening, a slidable door for said opening? a linkage connecting the Sill and door for actuating the door by movement of rthe Sill, said linkage compris- Ying; magnifying; lever, toggles between sill and lever and between leverand door, and a counteriveight angularly movable during opening of the door, Said counterweight providing a variable closing 'force during movement of the door. y

lnivitness whereof, I hereunto vsubscribe JAMES DART. 

